Railway signaling system



J. B. HARLOW.

RAILWAY SIGNALING SYSTEM.

APPLICATION FILED APR-20.1917.

Patented J 11116 29, 1920.

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UNITED, STATES PATENT oFric-a;

JOHN B. HARLOW, OF UPPER MONTCLAIR, -NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK.

' Application filed April 20,

To all whom it may concern:

Be it known that 1, Joint B. HARLOW, a citizen of the United States, .residim at Upper Montclair, in the county of Essex and State of New Jersey, have'invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a full, clear, concise, and exact description. This invention relates to railway signaling systems.

The object of this invention is to provide such a system by means of which semaphore signals, controlling the various blocks into which a railroad track is divided, may be selectively controlled from a central point, and the operator at the central po nt may be advised at all times of the condition of the semaphore signals.

In accordance with this invention, there is provided a signaling circuit extending from a central station along a railroad track, which is divided into sections. Associated with these sections are semaphore signals which may be' selectively controlled from a central station through the agency of selectors, connected with the line circuit at the various sections. Through the agency of the semaphore and a track relay con- 'trolled by the entrance of a train into a section other apparatus associated with each traclc section is adapted to transmit over the line circuit to the central station distinctive indications indicative of the condition of the semaphore signal of that section.

The drawing is a diagram of the apparatus and connections of a railway signaling system embodying this invention,

In the drawing A designates a central or receiving statlon. B and G designate sections of a railroad track along which extend line wires 5 and 6 connected to the receiving or central station A. The letters B and C may, however, designate the stations associated with these particular sections.

Located at the central station are impulse transmitting devices -7 and 8, in a local circuit including the source of energy 10 and the windings 11 of an impulse relay. The impulse transmitting device 7 is employed for controlling station B, and transmitter 8 is employed for controlling theapparatus of stat on C. The impulse relay includes normally open contacts 12 and 13 and nor- OF NEW YORK, N. Y., CORPORATION RAILWAY SIGNALING SYSTEM.

Specification of Letters Patent. Patented June 29, 1920.

1817. Serial N0. 163,395.

mally closed contact 14. The closure of the contacts 12 and 13 connects a source of current 15 with the line wires 5 and 6. The contact 14, in the operation of the impulse relay opens and closes a bridge of the line inclut mg a non-inductive resistance 16, said bridge being open when contacts 12 and 13 are closed, and closed when contacts 12 and 13 are open, the purpose being to provide a low resistance discharge path for retardation coils 17 17 and 18, 18, in series with the line wires and a condenser 19 in bridge of the line wires. The retardation coils and the condenser are for the purpose of graduuating the current impulses from the relay in order that they will not cause the disagreeable thump in telephonic apparatus which may be connected with the line wires during the transmission of impulses.

Located at track section B is a step-bystep selector circuit closing device comprising a quick-acting magnet 25'and a slowacting magnet 26 for operating the stepping and holding pawls 27 and 28, which control the movement of a ratchet wheel 29. Carried by the ratchet wheel 29 is a contact arm 30 adapted in the movement of said ratchet wheel to engage a contact spring 31. The selector is preferably arranged to beheld in its circuit closing position only when current is traversing the windings of its magnets which may be directly connected through a resistance to the ine wires 5 and 6. v

Associated with the track section B isa semaphore signal 40 which is shown in danger position. A. switch arm or brush is adapted to move with the blade of the semaphore 40, and when in danger position is in engagement with contact 51, and when in safety position, it is in engagement with contact 52, while, in passing'from contact 51 to 52, it is in engagement with a contact segment 53. The actuating motor of this signal is adapted to be controlled through the agency of a track relay 41 normally energized by means of a track battery 39, and the selector associated with track section B.

Also associated with the track section B is a motor 45 which is adapted to rotate a shaft 46, carrying code contact wheels 47, 48 and 49, which cooperate with the motor and with the contact arm 50, contacts 51 and 52, and segment 53, associated with the signal semaphore 40 to transmit to the central st ation characteristic code signals indicative of the position of the signal semaphore. Upon the shaft 46 is mounted av gear which meshes with a gear 56 on a shaft 57, which also carries two ham segments 58 and 59, the purpose of which will more fully hereinafter appear. The ratio between the gears 55 and 56 is such that while the shaft 57 is making one revolution, the shaft 46 makes eight. 7

At each section there is a control magnet 60 and answer back relay 61, which are controlled by the selector of that section to cause the signal semaphore 40 to be moved from danger to safety position, and which also control a motor relay 62 which controls the starting and stopping of the motor 45. The electromagnet 60 controls an armature 32 to which-is connected a pawl 33. The pawl is adapted to engage the teeth of a ratchet wheel 34, mounted upon one end of a shaft 36, upon the other end of which is mounted ,a cam segment 37. Associated with the cam segment 37 is a spring contact 'member 38 which, in the movement of the armature 32, cotiperates with the raised-and lowered surfaces of cam 37 to control contacts 42 a'hd 43. When the member 38 is in engagement with a lower surface of the cam 37,'contact 43 is closed and 42 open, and when riding upon one of the raised surfaces, it is adapted to open contact 43 and.

closecontact 42.

In addition, there is at the station B, a relay 63 which is normally energized and which coiiperates with the track relay 41 and the switching mechanism controlled by the control electromagnet 60 to switch the various circuits, whereby proper answer back signals are transmitted to the central stations. There is also a relay 64, the purpose of which will more fully hereinafter ap ear.

ssociated with track section C is apparatus exactly like that shown for" track section B, the position of the contact arm 30 of the selector being different from that at section B so that each selector will respond to a different combination of current impulses. Likewise the selectors provided at other track sections should have the contact arms 30 thereof positioned differently from those at track sections B and C. While separate transmitting keys 7'and 8 for controlling the selectors of track sections B and C have been illustrated, it is to be understood that there may be one master transmitting key such as is shown, in the Patent No. 1,155,640 to G. Brown, which may be set to control the sending out of a plurality of different combinations of impulses.

Referring to the operation of the system disclosed in the drawing, it will be assumed that the operator at the station A wishes 'its armature 32, partially rotating the shaft ingly, he will first operate the impulse transinitting device 7, which causes the intermittent operation of the impulse relay 11 to send current impulses from source 15 over the line wires 5 and 6. These impulses energize magnets 25 and 26 of the selector at station 15, causing the step-by-step advancement of the ratchet wheel 29 toclose contacts 30 and 31. Upon the closure of these contacts, control electromagnet 60 is energized and relay 61 is operated. Electromagnet 60, upon being energized, attracts 36, whereupon tie spring contact member 38 opens contact 43 and closes contact 42. Upon'the closure of contact 42, the actuating motor of the semaphore 40 begins to operate, the operating circuit therefor being from battery 70 through contact arm 50, t the actuating motor, contact 72 of track relay 41, contact 73 of relay 63 and contact 42 to ground. It takes approximately twenty seconds for the semaphore to move from danger to safety or clear position, and in moving from danger to safety position, the contact arm or brush 50 moves from contact 51 to segment 53, and when the signal is in full clear position, it rests on contact 52. When relay 61 operates upon the closure of the selector contacts, motor rela'y 62 operates, starting the motor 45, the operatingcircuit therefor being from battery 70 through the lower brush, armature and upper brush and field winding 74 of motor 45 and contact 75 of motor relay 62 to ground. Upon the operation of motor mag.-

net 62 and the rotation of the motor 45 and when the semaphore 40 is moving from .105 danger to clear position, a tone, produced by the counter electromotive force of the m0.-

tor 45, is heard in receiver 76 bridged across the line wires at the central station A. The

circuit over which the current producing this tone is transmitted may be traced from the lower brush of motor 45 through brush 50, segment 53, contact 77 of motor relay 62, condenser 78, line wire 6, receiver 76, line wire 5, condenser 79, contact 80 of re- 116 lay 62, and the upper brush and armature of motor 45. This tone received by the operator at station A' advises him that the semaphore is moving from danger to clear position. As the shaft 46, rotated by the 120 motor 45, begins to rotate, movement is also imparted to shaft 57, and when this shaft 57 is rotated a very short distance in the direction of the arrow, spring contact member 81 rides upon the raised portion of the 126 surface of cam 59 and closes contact 82, thereby establishing a locking circuit for motor relay 62 which may be traced from battery 83, contact 82, member 81, and winding of motor relay 62 to ground. It is to 130 be noted that the selector associated with the track section B is of the type which holds its contacts 30 and 31 in engagement only so long as current is on the line, and in this instance current will be on the line only so long as the impulse transmitting device 7 is in operation, which is for a comparatively short time. After transmitting key 7 has returned to normal position, and before the semaphore 40 has reached its full clear position, the shaft 57 will have made a complete revolution. When it has made a complete revolution, contact 82 is opened, thereby deenergizing the motor relay 62 and stopping the operatlon of the motor 45.

When the semaphore reaches its full clear position with the contact arm 50 in engage- 'ment with the contact 52,'motor relay 62 is operated over a circuit from battery through contact arm 50, contact 52, contact 84 of relay 64, and the Winding of motor relay 62 to ground. Upon the operation of the motor relay, the motor 45 is started, and

after the shaft 57 has been rotated in the direction of the arrow for a short distance, contact 82 is again made, reestablishing the locking circuit for motor relay 62. During the rotation of the motor, a coded answer back tone, controlled by code contact wheel 49 is produced in the receiver 76 at station A, indicating that the semaphore 40 has reached its full clea'r position. The circuit over which the current for producing this tone is transmitted may be traced from the lower brush of motor 45 through brush 50, contact 52, condenser 85, contact 86 controlled by code contact wheel 49, contact 77 of relay 62, condenser 78, line wire 6, receiver 76, line wire 5, condenser 79, contact 80 of relay 62, and the upper brush and armature of motor 451 Shortly before shaft 57 makes its complete revolution, that is, just prior to the member 81 dropping into the cutaway portion of the cam 59, the raised portion of cam 58 engages spring contact member 87, causing the closure of contact 88, whereupon relay 64 operates over a circuit from battery 70 through brush 50, contact 52, contact 88, member 87, winding of relay 64, contact 42 and member 38 to ground. Relay 64, in operating, completes a locking circuit for itself from battery 89 through contact 90 and the winding of relay 64. contact 42 and member 38 to ground. When the member 81 drops into the cutaway portion of the cam 59, contact 82 is opened, and since contact 84 of relay 64 is opened upon the operation of relay 64, the energizing circuit for the motor relay 62 will now be opened, and this relay will be released, stopping the motor.

Assuming now that a train or car 100 enters upon the track rails 101 of section B, track relay 41 will be short-circuited and will release its armatures, whereupon the circuit for the actuating motor of semaphore 40 will be opened and the semaphore will immediately go to danger, moving the brush 50 into engagement with contact 51. The release of track relay 41 opens the circuit of relay 63 which releases all of its armatures. Upon the release of its armatures by relay 63, motor relay 62 is operated over a circuit from battery '91 through contact 92 of relay 63, and the winding of relay 62 to ground. Upon the operation of motor relay 62, the motor 45 begins to rotate shafts 46 and 57. A distinctive answer back indication controlled by code contact wheel48 will now be given the operator at station A, indicating that a train has entered track section B, and that the semaphore 40 has gone to danger. The circuit over which the current for producing this distinctive answer back indication is transmitted may be traced from the lower. brush of motor 45 through brush 50, contact 51, contact 93 of relay 63, contact 94 controlled by code contact wheel 48, contact 77 of motor relay 62, condenser 78, line wire 6, receiver 76, line wire 5, condenser 7 9, contact-80 of motor relay 62,- and the upper brush and armature of motor 45. This indication will continue so long as contact 93 of relay 63 remains closed, and is not affected by the passing of a train out of this particular section. This distinctive answer back indication may be stopped by the operator at station A by the actuation of the transmitting key 7, which causes the selector of track section B to close its contacts 30 and 31, whereupon .controlling electromagnet 60 operates, opening contact 42 and closing contact 43. Upon the closure of contact 43, relay 63 operates over a circuit from battery 95, winding of relay 63, contact 43, and member 38 to ground. Also upon theopening of contact 42, relay 64 is released. Since relay 62 will be operated so long as contact 82 is closed, if relay 64 is released and relay 63 operated while contact 82 is closed, the motor will continue its rotation, whereupon a distinctive answer back code indication controlled by. code contact wheel 47 and indicating that the control apparatus actuated by relay 60 has been returned to its normal position. and that relay 63 is operated and relay 64 released, will be produced in the receiver 7 6 at station A. The circuit over which the current for producing this distinctive code indication is transmitted may be traced from the lower brush of motor 45 through brush 50, contact 51, contact 96 of relay 63, contact 97 controlled by code contact wheel 47,

' dition of the semaphores, and he can at all times know whether a particular semaphore which he desires to move to clear position has actually moved.

l/Vhile a plurality of batteries have been shown in track section B, it is to be understood that this is for convenience only and that in practice'there is only one battery employed for controlling the signal apparatus at each section. It should be understood, however, that the track battery is entirely separate from that controlling the signal control apparatus.

What is claimed is:

1. In a railway signaling system, a line circuit, a signal member adapted to be moved to two positions, means controlled over the line circuit for moving the signal member to one position, a section of railroad track, means controlled by the entrance of a train into the section for causing the signal member to move to the other position, an answer back mechanism associated with the signal member for producing when operated a plurality of characteristic signals, and switching mechanism controlled by the signal member and cooperating with and causing the answer back mechanism to transmit over the line circuit an answer back signal of one character while the signal member is moving to the one position and an answer back signal of another character when the signal member moves into the one position.

2. In a'railway signaling system, a section of railroad track, a signal semaphore associated with the track section and adapted to be moved to two positions, a dis tant station, a line circuit extending from the station to the track section, means controlled over the line circuit from the distant station for moving the signal semaphore to clear position, means controlled by the entrance of a train into the .track section for causing the signal semaphore to move to danger position, an answer back mechanism associated with the track section for producing when operated a plurality of charac-' teristic answer back signals, and switching mechanism controlled by the signal semaphore and cooperating with and causing the answer back mechanism to transmit over the line circuit an answer back signal of one character while the signal is being moved from danger to clear position, an answer back signal of another character when the signal semaphore reaches the clear position, and cooperating with the train controlled means to cause the answer back mechanism to transmit an answer back of still another character when the signal semaphore reaches danger position.

3. In a railway signaling system, a railroad track divided into sections, a distant station, a line circuit extending therefrom along the track, a signal semaphore at each of characteristic answer back signals, and

switching mechanism controlled by each signal semaphore and cooperating with and causing the associated answer back mechanism to transmit to the distant station an answer back signal of one character while the signal semaphore is moving from danger to clear position and an answer back signal ofanother character when the signal semaphore reaches clear position.

4. In a railway signaling system, a railroad track divided into sections, an answer back mechanism associated witheach of the sections for producing when operated a plurality of characteristic signals, a signal semaphore at each section adapted to be moved to two positions, an actuating circuit I for the signal semaphore, a selectively operated device for completing the actuating circuit to move the signal semaphore to clear position, means controlled by the entrance of a train into the section for opening the actuating circuit permitting the movement of the previously moved signal signal of another character when the signal semaphore reaches clear position and a signal of another character when the signal semaphore is in danger position.

5. In a railway signaling system, a signal semaphore adapted to be moved to two positions, means for moving the signal semaphore to clear position, an answer back mechanism including a plurality of codifying devices, an answer back circuitv completed while the signal semaphore is moving to danger position, a switching device operated when the signal semaphore is in clear position to include one of the codifying devices in the answer back circuit, means for moving the signal semaphore from clear to danger position, and a switching device operated When the signal semaphore is in danger position to include another of the codifying devices in the answer back circuit. 'i

6., In a system of the class described, a signal element adapted to be moved to two positions, means for moving the signal element into one position, answer back mechanism including a plurality of codifying de-' vices, an answer back circuit completed while the signal element is moving to the one position, a switching device controlled by and operated when the signal element is in the one position to include one of the codifying devices in the answer back circuit, means for moving the signal element from the one position into its other osition and said switching device controlled by and operated when the signal element 'is in its other position to include another of the codifying devices in the answer back circuit. 7. ha railway signaling system,'a railroad track divided into sections, a central station, a line circuit extending from the central station along the track sections, a signal semaphore for each section adapted to be moved to two positions, answer back mechanism individual to each section and including a plurality of codifying devices,v

signal semaphore is in clear position to include one of the codifying devices in the answer back circuit, a track relay actuated upon the entrance of a train into the section for opening the actuating circuit to permit the signal semaphore to move to danger the line circuit from the central station for operating the control switch to thereby close the actuating circuit to move the signal semaphore to clear position, an answer back mechanism individual to each section and including aplurality of codifying devices, an answer back circuit completed While the signal semaphore is moving to clear position, a relay operating under control of the selectively operated device to connect the answer back circuit with the line circuit, a switching device operated when the signal semaphore is in clear position to include one of the codifying devices in the answer back circuit, a track relay responsive to the entrance of a train in the section to open the actuating circuit to permit the movement of the signal semaphore to danger position,

said switching device operated when the signal semaphore is in dan er position to include another of the co if mg devices in the answer back circuit, and device operative upon the subsequent operation of the control switch to include still another of the codifying devices in the answer back circuit.

In witness whereof I hereunto subscribe my name this 19th day of April, A. D. 1917.

JOHN B. HARLOW,

said switching 

